Selective recovery method of vanadium and cesium from waste sulfuric acid vanadium catalyst, and high-quality vanadium aqueous solution and cesium alum produced thereby

Abstract

Provided are a selective recovery method of vanadium and cesium from a waste sulfuric acid vanadium catalyst by a hydrometallurgical method including water leaching, solid-liquid separation, vanadium solvent extraction, vanadium selective stripping, and cesium alum production, and a high-quality vanadium aqueous solution and cesium alum produced thereby.

What is claimed is: 
     
       1. A selective recovery method of vanadium and cesium from a waste sulfuric acid vanadium catalyst containing vanadium, cesium, iron, silica, aluminum, potassium, sodium, calcium and titanium by a hydrometallurgical method including water leaching, solid-liquid separation, vanadium solvent extraction, vanadium selective stripping and cesium alum production, the selective recovery method comprising the steps of:
 (a-1) crushing and pulverizing a waste sulfuric acid vanadium catalyst; 
 (a-2) water-leaching the crushed and pulverized waste sulfuric acid vanadium catalyst and then solid-liquid separating to prepare a waste sulfuric acid vanadium water leachate containing vanadium and cesium in a cationic state; 
 (a-3) adding an organic solvent as a cation exchange extractant to the waste sulfuric acid vanadium water leachate containing vanadium and cesium in the cationic state to obtain a vanadium organic extract from which vanadium is solvent-extracted and a raffinate aqueous solution remaining after the solvent extraction of vanadium; 
 (a-4) preparing a vanadium aqueous solution by adding an alkali aqueous solution to the vanadium organic extract to selectively strip vanadium; and 
 (a-5) selectively recovering cesium from cesium alum precipitated by adding and reacting an aluminum compound to the raffinate aqueous solution obtained after the vanadium solvent extraction and cooling a mixture. 
 
     
     
       2. The selective recovery method of  claim 1 , wherein in (a-1) the crushing and pulverizing of the waste sulfuric acid vanadium catalyst,
 the waste sulfuric acid vanadium catalyst is crushed and pulverized by at least one device selected from the group consisting of jaw crusher, gyratory crusher, roller crusher, cone crusher, hammermil crusher, tumbling mill, vibration mill, attrition mill, ball mill, rod mill, pebble mill, and autogeneous mill to prepare the crushed and pulverized waste sulfuric acid vanadium catalyst, and 
 a particle size of the crushed and pulverized waste sulfuric acid vanadium catalyst is 10 to 500 mesh. 
 
     
     
       3. The selective recovery method of  claim 1 , wherein in (a-2) the water-leaching of the crushed and pulverized waste sulfuric acid vanadium catalyst and then solid-liquid separating to prepare the waste sulfuric acid vanadium water leachate and a leaching residue,
 the water-leaching condition is 10 minutes to 12 hours under conditions of a reaction temperature of 25 to 80° C., a solid-liquid ratio of 1/10, and a stirring rate of 50 to 500 rpm by adding the crushed and pulverized waste sulfuric acid vanadium catalyst to water. 
 
     
     
       4. The selective recovery method of  claim 3 , wherein the vanadium leaching rate of the waste sulfuric acid vanadium water leachate is 10 to 99.9 wt %. 
     
     
       5. The selective recovery method of  claim 1 , wherein in (a-3) the adding of the organic solvent as the cation exchange extractant to the waste sulfuric acid vanadium water leachate containing vanadium and cesium in the cationic state to obtain the vanadium organic extract from which vanadium is solvent-extracted and the raffinate aqueous solution remaining after the solvent extraction of vanadium,
 the organic solvent is at least one selected from the group consisting of 2-ethyl hexyl phosphonic acid, di-2-ethylhexyl phosphoric acid, mono-2-ethyl hexyl ester, bis-(2,4,4-trimethylpentyl) phosphinic acid, alkyl monocarboxylic acid, tributyl phosphate, and trialkylphosphine oxide. 
 
     
     
       6. The selective recovery method of  claim 1 , wherein in (a-3) the adding of the organic solvent as the cation exchange extractant to the waste sulfuric acid vanadium water leachate containing vanadium and cesium in the cationic state to obtain the vanadium organic extract from which vanadium is solvent-extracted and the raffinate aqueous solution remaining after the solvent extraction of vanadium,
 the organic solvent is an organic solvent having a degree of saponification of 1 to 15%, and 
 the organic solvent is at least one selected from the group consisting of 2-ethyl hexyl phosphonic acid, di-2-ethylhexyl phosphoric acid, mono-2-ethyl hexyl ester, bis-(2,4,4-trimethylpentyl) phosphinic acid, alkyl monocarboxylic acid, tributyl phosphate, and trialkylphosphine oxide. 
 
     
     
       7. The selective recovery method of  claim 5 , wherein in (a-3) the adding of the organic solvent as the cation exchange extractant to the waste sulfuric acid vanadium water leachate containing vanadium and cesium in the cationic state to obtain the vanadium organic extract from which vanadium is solvent-extracted and the raffinate aqueous solution remaining after the solvent extraction of vanadium,
 an experimental condition for extracting vanadium with the organic solvent is 2 minutes to 30 minutes under the conditions of a reaction temperature of 15 to 40° C., O (organic phase)/A (water phase)=1 to 4, and a stirring rate of 50 to 500 rpm by adding the organic solvent to the waste sulfuric acid vanadium water leachate. 
 
     
     
       8. The selective recovery method of  claim 5 , wherein the vanadium extraction rate of the vanadium organic extract extracted using the organic solvent is 25 to 95 wt % at pH 1 to 6. 
     
     
       9. The selective recovery method of  claim 6 , wherein in (a-3) the adding of the organic solvent as the cation exchange extractant to the waste sulfuric acid vanadium water leachate containing vanadium and cesium in the cationic state to obtain the vanadium organic extract from which vanadium is solvent-extracted and the raffinate aqueous solution remaining after the solvent extraction of vanadium,
 an experimental condition for extracting vanadium with the organic solvent is 2 minutes to 30 minutes under the conditions of a reaction temperature of 15 to 40° C., O (organic phase)/A (water phase)=1 to 4, and a stirring rate of 50 to 500 rpm by adding the organic solvent having the degree of saponification of 1 to 15% to the waste sulfuric acid vanadium water leachate. 
 
     
     
       10. The selective recovery method of  claim 6 , wherein the vanadium extraction rate of the vanadium organic extract extracted using the organic solvent having the degree of saponification of 1 to 15 wt % is 65 to 99.5 wt %. 
     
     
       11. The selective recovery method of  claim 1 , wherein in (a-3) the adding of the organic solvent as the cation exchange extractant to the waste sulfuric acid vanadium water leachate containing vanadium and cesium in the cationic state to obtain the vanadium organic extract from which vanadium is solvent-extracted and the raffinate aqueous solution remaining after the solvent extraction of vanadium,
 the raffinate aqueous solution contains Na, Cs, or K. 
 
     
     
       12. The selective recovery method of  claim 1 , wherein in (a-4) the preparing of the vanadium aqueous solution by adding the alkali aqueous solution to the vanadium organic extract to selectively strip vanadium,
 the alkali aqueous solution is at least one alkali aqueous solution selected from the group consisting of (NH 4 ) 2 CO 3 , NaOH, and Na 2 CO 3  in a concentration range of 0.05 to 5 M. 
 
     
     
       13. The selective recovery method of  claim 12 , wherein the vanadium stripping rate of the vanadium aqueous solution is 70 to 99.99 wt %. 
     
     
       14. The selective recovery method of  claim 1 , wherein in (a-5) the selectively recovering of the cesium from the cesium alum by adding the aluminum compound from the raffinate aqueous solution obtained after the solvent extraction of vanadium,
 the aluminum compound is at least one selected from the group consisting of aluminum chloride, sodium aluminate, aluminum powder, aluminum hydroxide, aluminum sulfate, and alumina. 
 
     
     
       15. The selective recovery method of  claim 14 , wherein when the cesium alum is formed in the (a-5) raffinate aqueous solution, the cesium precipitation rate is 60 to 98 wt %. 
     
     
       16. The selective recovery method of  claim 15 , wherein the purity of the cesium alum is 90 to 99.1 wt %.